Combination knee and ankle joint



June 1953 R. w. M KENDRICK COMBINATION KNEE AND ANKLE JQINT 3 Sheets-Sheet 1 Filed April 8, 1948 3 Sheets-Sheet 2 R. W. M KENDRICK COMBINATION KNEE AND ANKLE JOINT June30, 1953 Filed April 8, 1948 June 1953 R; w. M KENDRICK COMBINATION KNEE AND ANKLE JOINT 3 Sheets-Sheet 3 sh x IIIHIIIIIHIIH Filbd April 8, 1948 (Ittorneg Patented June 30, 1953 UNITED STATES PATENT OFFICE COMBINATION KNEE AND ANKLE JOINT Roderick W. McKcndrick, Salt Lake City, Utah Application April 8, 1948, Serial No. 19,823 13 Claims. ((31. 3-2) My invention relates to artificial limbs and has for its object to provide a new and highly efficient combination knee and ankle joint adapted to operate in the identical manner that the original limb operated the knee and angle to take and assume the same movements and twists that the original limb took before amputation.

A further object is to provide a functional knee point for above the knee artificial limbs which will eliminate many parts, and much expensive material and which will accomplish a better result than possible with the old style knee joint or with certain highly complex knee joints recently developed.

A still further object is to provide a self-aligning knee and ankle combination artificial limb which is so constructed that when used it will align itself to the diiierent individual movements and oddities each individual has in their walking habits, and which will compensate for and assume the correct movements to make movements of the limbs natural for a person having knock knees, bow legs, or other like differences of body formation and with the knee adaptable for adjustment up or down one fourth inch totaling one half inch in adjustment for height which is a much greater distance for adjustment than has heretofore been possible with artificial limbs.

A still further object is to provide an artificial limb which gives free action on front and back a motion, lateral motion and rotation in the knee thus providing freedom of movement never possible with any artificial limb.

A still further object is to provide a brake and lock in the knee joint controlled by the position of the toe and leg to meet the individual needs of each person needing such a limb.

in manufacturing such a limb the points of rotation can be varied as much as twenty-five per cent from extreme knock knee to extreme 20w legged types in five minutes time without changing the construction of the original installation which will out down construction costs and labor at least four hours for each artificial limb, and often will save as high as one entire day usually spent in alignment and fitting.

These objects I accomplish with the device illustrated in the accompanying drawings in which similar numerals and letters of reference indicate like parts throughout the several views and as described in the specifications forming a part of this application and pointed out in the appended claims.

Figure 1 is a side View of an artificial limb of my design. i

2 i Figure 2 is a rear view thereof.

Figure 3 is an enlarged vertical section of the knee and ankle joint medial portions cut away.

Figure 4 is a transverse section of the knee joint.

Figure 5 is a transverse section of the ankle joint.

Figure 6 is a view of the ball and socket used in the ankle joint.

Figure '7 is an end view of Figure 6.

Figure 8 is a view of the ankle shaft removed from the ball.

Figure 9 is an exploded view of the ball and socket the ball being removed from the socket.

Figure 10 is a view of the socket support and bolt.

Figure 11 is an end view of the ball and socket used in the knee joint.

Figure 12 is a view of the shaft used in the knee joint.

Figure 13 is an exploded view of the ball and socket used in the knee joint.

Figure 14 is a view of the socket support bolt used in the knee joint.

Figure 15 is a plan view of the knee adjusting plate for vertical adjustment.

Figure 16 is a diagrammatical section of Figure 15.

In the drawings I have shown the artificial leg as the socket A into which the stump is fitted in the usual manner. The socket A is joined to the medial leg or knee to ankle section B of the log by a special joint and the foot C is joined by a similar new ankle joint, the entire assembly providing a new artificial limb having many adjustments not possible with the usual artificial limbs, yet using substantially the same joints in the knee joint in the ankle joint, the ball and socket portions being absolutely identical except in some instances they will be of different sizes, but in most cases these two joints will be identical.

Each joint consists of an eyebolt having a shaft threaded to receive a nut or to be screwed down into a socket depending upon its use as an ankle or a knee joint. This eyebolt carriers a socket therein in which a ball is mounted the ball be ing provided with a hole through which a shaft is passed, the shaft being locked in the position required whether it be the knee or ankle. These features are essentially identical in both joints.

Describing the knee joint first I will illustrate the eyebolt as 5, carrying a socket 6 and ball 1,. through which ball the shaft 8 is passed. Thesocket A is provided with a vertical cut Din theback of the knee and the joint is mounted therein with rubber bumpers or washers 9 and I mounted one on each side of the joint with the shaft 8 extending from outside to outside of the leg. This joint is set much farther back than is the usual manner and is braced by the forwardly extending leg portion [0 engaging the knee cap portion of the leg as shown in Figure 3, as well as by the body of the stump engaging the socket ll into which the threaded eyebolt is screwed. Each end of the shaft 8 is held in place by a set screw [2. The knee is attached to the leg portion B by securing the internally threaded socket or eyebolt receiver l-3 first to the plate I4 of the leg by the bolts I4 being passed through the flange l6 and then by screwing the eyebolt down into the receiver 13 and when properly adjusted for height and throw the eyebolt is locked in position by a set screw H. The eyebolt receiver I3 is formed centrally on the round flange l6 and the-flange is secured onto the plate [4 by four bolts l5.

Where it is not desired to use the brake and lock on the knee joint this finishes thejoint with the exception that the lower end of the slot D in the socket A is formed with. arcuate cuts 18 and I9, to permit a certain amount of lateral movement which movement will, of course, be compensated for and the shock in the rubber bumpers or washers 9 and I I].

Where it is desired to have the relativeposition of the toe or foot control a brake to lock the knee joint from buckling or other movement, the eyebolt is cut and provided with extended cars 26 and 2t with a bolt hole bored therethrough to receive a bolt 22 carrying a brake lever 23,. This lever'23'extends back and has a'cable 24 attached to the end thereof,-and when the cable, 2 is drawn down the lever 23 will be moved, acting as a brake lever drawing the two cars 20 and 2i together constricting the bore of the eyebolt onto the socket.6;,locking the knee joint from movement. The lower end of the cable 24 is attached to a ball 25 which is carried in an adjustable receiver 23 mounted in the foot C, with the receiver being held in place by the bolt end 21 receivinga nut 23', carried in a socket 29 in the bottom of the foot forward of the arch of the foot. The cable is passed through a bore 30 in the leg and a hole 3| in the'fiange'lfi.

The ankle joint is substantially identical to the knee joint but separate numerals will be given the various'parts for clarity. The ankle joint is composed of an eyebolt 32, socket 323, a ball, and a shaft 35 is passed through the central hole in the ball 34. This shaft 35 is secured in place in the foot C by set' screws or bolts 35 passed up through the foot and into the shaft'ends as shown in Figure 5. This assembly is then set in a solid one piece rubber bushing R. The rubber bushing may be square in cross section as shown in Figure'5, or may be round if desired, the essential feature being only that it'take up and bush excessive thrust from end motion'as well as side motion and that it permit ankle'movement which may be thrust, twist or rocking motion; A nut 31 is carrying a 4 eyebolt to provide for the desired tension in the foot ankle joint relationship and other adjustments may be made in the knee joint to adjust for twist, throw, and other unusual individual motions inherent to the individual using the leg. For instance in some cases the set screw 11 will be left loose until the knee assumes its relative position to meet the requirements of the individual before the set screw is locked in position.

Having thus described my invention I claim:

1. An artificial leg comprising a universally rotatable ball and socket joint in the ankle and a universally rotatable ball and socket joint in the knee, and resilient means associated with the respective ball and socket joints for returning the adjoining limbs to normal position following displacement thereof.

2. An artificial leg comprising a universally rotatable ball and socket ankle joint having a transverse shaft passed through the center of the ball of the joint with its opposite ends anchored in the foot portion of the leg, said resilient material being anchored in said leg and in said foot against displacement but not elastic deformation in a plane substantially normal to the longitudinal axis of the leg; resilient material disposed on all sides of said ball and socket joint as a cushion between said foot portion and the lower leg portion of said leg; and a shank extending from the socket member of said joint up into the lower leg portion of said leg, thereby attaching the said foot portion to said lower leg portion and permitting partial rotary as well as the usual rocking motion for said foot.

3. An artificial leg comprisin a foot; a lower leg portion, said foot being recessed to receive the lower end of the lower leg portion as the ankle; a universally rotatable ball and socket joint having the ball attached to the foot and the socket attached to the said lower leg portion; and resilient means surrounding the ball and socket joint, and anchored in said lower leg and in said foot against displacement but not elastic deformation in a plane substantially normal to the longitudinal axis of the leg.

l. In an artificial leg having a foot member and an upper leg member articulatively attached to a lower leg member at respectively opposite ends thereof, a universally rotatable ball and socket joint forming articulative connection between the foot member and the lower leg memher; a universally rotatable ball and socket joint forming the articulative connection between the upper leg member and the lower leg member; and resilient means anchored in said lower leg and in said foot against displacement but not elastic deformation in a plane substantially normal to the longitudinal axis of said leg.

5. The combination recited in claim 4, wherein the ball members of the said joints are secured to the foot member and the upper leg member, respectively, by means of respective shafts which pass through the centers of said ball members and provide transverse rotative axes therefor.

6. The combination recited in claim 5, wherein the socket members of the said joints are respectively secured to the lower leg member by means of respective shanks extending rigidly from said socket members.

7. The combination recited in claim 6, wherein the said shank members have threaded anchorages withrespect to the lower leg member so the respective joints are adjustable to satisfy individual requirements.

8. The combination recited in claim 7, wherein the said joint between the foot member and the lower leg member is surrounded by resilient material which provides a cushion between said foot member and said lower leg member.

9. In an artificial leg having a foot member articulatively attached to a lower leg member, a ball and socket joint providing the articulative connection, the ball and socket members of said joint being interfitted for free universal rotative movement; means anchoring the ball member of said joint to said foot member, including a shaft passing through the center of said ball member and providing a transverse rotative axis therefor; means securing the socket member of said joint to said lower leg member, including ashank extending rigidly from said socket member and passing upwardly into a hollow portion of said lower leg member through a bore provided in the latter, and a head threaded on the upper end of said shank, said head bearing downwardly against said lower leg member and being movable upwardly within said hollow; and resilient means between said lower leg member and said foot member, said resilient means including a block of resilient material within which said ball and socket joint is embedded.

10. In an artificial leg having a foot member articulatively attached to a lower leg member, a universally rotatable ball and socket joint providing the articulative connection, and having the ball member thereof secured to the foot member of the leg by means of. a shaft passing through the center of said ball member to provide a transverse rotative axis therefor; and resilient means anchored in said low leg and in said foot against displacement but not elastic deformation in a plane substantially normal to the longitudinal axis of said leg.

11. The combination recited in claim 10, wherein the socket member of the joint is secured to the lower leg member of the leg by means of 6 a shank extending rigidly from said socket member.

12. The combination recited in claim 11, wherein the shank of the socket member of the joint extends upwardly into a hollow portion of the lower leg member of the leg through a bore provided in said lower leg member for the purpose; resilient means is provided between the foot member and the lower leg member on all sides of said ball and socket joint; and the upper end of said shank is provided with a head bearing downwardly against the lower leg member and movable upwardly within said hollow, whereby cushioned relative movement is provided for between the foot member and the lower leg member of said leg.

13. The combination recited in claim 12, wherein the head of the shank is threaded on the end of the shank, so that the resilient means may be adjustably compressed in accordance with individual requirements.

RODERICK W. McKENDRICK.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 42,799 Shepard May 1'7, 1864 409,311 Snyder Aug. 20, 1889 1,001,641 Harrison Aug. 29, 1911 1,283,093 Critchley Oct. 29, 1918 2,098,067 Simonsson Nov. 2, 1937 2,289,154 Van Cise July 7, 1942 2,309,281 Steele Jan. 26, 1943 2,336,881 Mortensen Dec. 14, 1943 FOREIGN PATENTS Number Country Date 309,817 Italy July 17, 1933 361,623 Germany May 18, 1921 656,219 Germany Jan. 31, 1938 690,752 Germany May 6, 1940 

